Various substituted tetrazoles are known, including the compound 3-(1H-tetrazol-5-yl)quinoline, reported in J. Med. Chem. 10, 149 (1967). However, no compounds wherein a tetrazole ring is substituted by a 3-(4-hydroxyquinolyl) group are believed to have been known prior to the present invention, nor has the anti-allergic activity of the compounds of the present invention been recognized.